This submission provides the files used in the webinar presentation, "Model-Based Design of Landing Gear".
In this presentation, we demonstrate how Model-Based Design (MBD) can be used for the development of flight landing systems. We create and show flight simulations of landings of NASA?s HL20 lifting body design. We show that to employ Model-Based Design successfully for landing gear systems, your simulations must represent the aerodynamic loads and the activity of the flight control system leading up to the landing. The outcome of this effort is identification of the force magnitude requirement for the hydraulic actuation of the landing gear linkage.
We focus on the risky scenario of the one-wheel landing. Such a landing occurs in real life when wind bursts tilt the vehicle such that one wheel is positioned to touch before the others. If such a burst occurs just prior to touch down, the flight control system lacks the time to correct the vehicle?s positioning. These situations are risky because they can introduce side loading that is capable of collapsing the linkage and crashing the vehicle. To analyze a system subject to this risk, the mechanical linkage requires full modeling to account for the non-linear dynamics. The understanding of this mechanical dynamics can be the difference between a successful design and one prone to catastrophic failure.
The demonstration that is shown employs Aerospace Blockset for building aerodynamics models. This blockset includes air density vs altitude, and wind turbulence models that are the standards of the industry. The mechanical linkage model is delivered through SimMechanics: a tool for building such models based on the principles of rigid-body dynamics. The offering of these tools through Simulink, where the flight control system is defined, enables a solution provided through a single simulation platform.
From a broad perspective, this work addresses the significant needs of those developing mechanical systems that are subject to flight loads. The connection of flight mechanics and linkage mechanics, which is established by this joint solution of SimMechanics, Aerospace Blockset and Simulink, offers considerable value to those developing such applications.
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